• Applied Microscopy
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• 제45권4호
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• pp.203-207
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• 2015

Sample preparation is very important for crystal structure analysis of novel nanostructured materials in electron microscopy. Generally, a grid dispersion method has been used as transmission electron microscope (TEM) sampling method of nano-powder samples. However, it is difficult to obtain the cross-sectional information for the tabular-structured materials. In order to solve this problem, we have attempted a new sample preparation method using focused ion beam. Base on this approach, it was possible to successfully obtain the electron diffraction patterns and high-resolution TEM images of the cross-section of tabular structure. Finally, we were able to obtain three-dimensional crystallographic information of novel zeolite nano-crystal of the tabular morphology by applying the new sample preparation technique.

• 한국전자현미경학회:학술대회논문집
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• 한국현미경학회 1995년도 제26회 춘계학술대회 연제초록
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• pp.50-51
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• 1995

• 한국재료학회:학술대회논문집
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• 한국재료학회 1995년도 추계 학술발표 강연 및 논문개요집
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• pp.25-26
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• 1995

• Journal of Microbiology and Biotechnology
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• 제23권9호
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• pp.1287-1292
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• 2013

Extracellular biogenic synthesis of silver nanoparticles with various shapes using the rice bacterial blight bacterium Xanthomonas oryzae pv. oryzae BXO8 is reported. The synthesized silver nanoparticles were characterized by UV-Vis spectroscopy, powder X-ray diffractometry (XRD), scanning electron microscopy, energy dispersive X-ray spectrometry, and high-resolution transmission electron microscopy (HR-TEM). Based on the evidence of HR-TEM, the synthesized particles were found to be spherical, with anisotropic structures such as triangles and rods, with an average size of 14.86 nm. The crystalline nature of silver nanoparticles was evident from the bright circular spots in the SAED pattern, clear lattice fringes in the high-resolution TEM images, and peaks in the XRD pattern. The FTIR spectrum showed that biomolecules containing amide and carboxylate groups are involved in the reduction and stabilization of the silver nanoparticles. Using such a biological method for the synthesis of silver nanoparticles is a simple, viable, cost-effective, and environmentally friendly process, which can be used in antimicrobial therapy.

• 한국세라믹학회지
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• 제37권11호
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• pp.1126-1129
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• 2000

The crystallographic orientations of $Ba_{0.6}$S $r_{0.4}$Ti $O_3$(BST) thin film deposited by a metal-organic chemical vapor deposition on (111) textured Pt electrode were studied with a transmission electron microscopy. The fully crystallized BST thin film (50nm) has (100) and (110) preferred orientations. A high resolution transmission electron microscopy study has revealed the crystallographic orientation relationships between BST thin film and Pt electrode. These relationships explained the preferred orientation of BST film on (111) textured Pt electrode. With these results, we could represent the atomic arrangement at the BST/Pt interface.e.e.

• Applied Microscopy
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• 제45권4호
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• pp.195-198
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• 2015

Gas-assisted etching (GAE) with focused ion beam (FIB) was applied to prepare plan-view specimens of Cu thin-layer on a silicon substrate for transmission electron microscopy (TEM). GAE using $XeF_2$ gas selectively etched the silicon substrate without volume loss of the Cu thin-layer. The plan-view specimen of the Cu thin film prepared by FIB milling with GAE was observed by scanning electron microscopy and $C_S$-corrected high-resolution TEM to estimate the size and microstructure of the TEM specimen. The GAE with FIB technique overcame various artifacts of conventional FIB milling technique such as bending, shrinking and non-uniform thickness of the TEM specimens. The Cu thin film was uniform in thickness and relatively larger in size despite of the thickness of <200 nm.

• Applied Microscopy
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• 제35권3호
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• pp.105-112
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• 2005

고분해능 TEM 영상 이론의 결맞음 조사에서의 결맞음에 관한 개념을 소개하였다. 현미경에서 부분 결맞음 파동으로 인한 transfer function과 envelope의 발생을 설명하고 현미경의 분해능과 관련된 passband와 Scherzer 초점 조건을 소개하였다.

• 분석과학
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• 제5권1호
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• pp.121-126
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• 1992

GaAs ${\Sigma}=19$, [110] tilt grain boundary의 구조를 투과전자현미경을 이용하여 연구하였다. Higher-Order Laue-Zone(HOLZ) 빔들과 {200} 빔과의 dynamical coupling 결과를 검토하여 입계 양쪽 각각의 입자(grain) 내 Ga-As의 상대적 위치(방향성)를 결정하였으며, 두 입자 사이에는 inversion symmetry가 결합되지 않은 ${\Sigma}=19$ coincidence에 해당하는 교차각이 있었다. 계면은 $\{331\}_A/\{331\}_B$, [110] 결정면을 따라서 발생하는 경향이 강함을 관측했다. 이 facet에서의 원자구조 및 격자이동 등을 고분해 투과전자현미경을 이용하여 밝혔다. 5-, 7-, 그리고 6-member ring의 조합으로 되어 있는 단위를 계면원자구조 model로 제시했다.

• 소성∙가공
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• 제33권2호
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• pp.118-122
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• 2024

Micro-electromechanical systems (MEMS) based in-situ heating holders have been developed to enable high resolution imaging of heat treatment analysis. However, unlike the standard 3 mm metal disk specimens used in the furnace-based heating holder and general transmission electron microscopy holder, the MEMS-based in-situ heating holder requires thin specimens that can be penetrated by electrons to be transferred onto the MEMS chip. Previously, focused ion beam milling was used to transfer metal specimens, but it has the disadvantage of being expensive and the risk of specimen damage due to gallium ions. Therefore, in this study, we devised a method of transferring metallic materials by ultrasonic treatment using a transmission electron microscopy specimen made by electro jet polishing. A 3mm electropolished metal disk was placed in an appropriate solution, ultrasonicated, and then drop casted. The transfer of the specimen was successful, but it was confirmed that dislocations were formed inside the specimen due to ultrasonic treatment. This study provides a novel method for transferring metallic materials onto MEMS chips, which is cost-effective and less gallium ion damaging to the specimen. The results of this study can be used to improve the efficiency of heat treatment analysis using MEMS-based in-situ heating holders.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1993년도 추계 학술발표 강연 및 논문 개요집
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• pp.150-151
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• 1993